Hooking up the world's greatest spam filters

Gmail has the world's greatest spam filters. They process billions of emails everyday and they own Postini. Today, I hooked up a client's website email to Google's spam filters using Google Apps. I had to change his MX records in his hosting account cPanel. The change over was instant, though they say it could take a couple of days to take effect. I know it was instant, because he was collecting junk in his spam box right away. So now email sent to his domain goes to Gmail in his Google Apps account. From here I can set up his Gmail for POP access, and configure his email client with the Gmail settings and he'll get no more spam! Way cool. I have a bunch of clients who get tons of spam. I think they are going to like this.